Space Shuttle Challenger Explosion Essay, Research Paper
7 December 1999
The Challenger Space Shuttle Disaster
The morning was clear, bright, and cold on January 28th, 1986, in Cape Canaveral,
Florida. The skies were clear allowing the sun to shine over the launch area at the
Kennedy Space Center and attempt to increase its freezing temperature. On launch pad
39B icicles dangled from the launch tower, pad structure, and other launch equipment
(Lewis 127) as the space shuttle Challenger stood in a powerful vertical silhouette against
the morning light. The shuttle, solid rocket boosters, and external tank had been on the
pad for thirty-eight days, and in that duration seven inches of rain had fallen causing the
ice build-up (Mahal). Various project members for mission 51-L carried out their duties at
the launch site preparing for the shortcoming of the tenth flight of the orbiter, Challenger.
Busses unloaded spouses, children, and parents of the shuttle crew at the VIP
observation site three and a half miles away from the launch pad (Lewis 1). This new site,
closer than usual, gave family, friends, and press a greater sense of involvement in the
launch. Positioned as they were between the press grandstand, network television
platforms, and towering stockade of the vehicle assembly building and launch control
center (McConnell 136), all peoples? senses awaited the 11:38 a.m. ET lift-off with
anticipation. It was launch day at the Kennedy Space Center.
After five days of delay filled with wind, rain, and frustration, Challenger was
finally ready to go on mission 51-L, the twenty-fifth mission for the world?s first fleet of
reusable manned spaceships (Lewis 1). Public interest in the flight had been focused by a
strong public-relations climax on the first private citizen to fly aboard a space shuttle.
Sharon Christa McAuliffe, age 37, was a high school teacher who had been selected
through the National Aeronautics and Space Administration?s (NASA) sweepstakes from
more than 11,000 applicants (The Crew?) to be the first teacher in space. Her
assignment was to demonstrate and explain the effects of microgravity in the context of
Newtonian physics and the scientific, commercial, and industrial applications of space
flight. She then was to address an audience of schoolchildren via television from the
spacecraft (Lewis 1). The presence of this personable and attractive young woman added
a new dimension to the public?s perception of the space program. Space flight in America
was no longer just the exclusive rights of astronauts, scientists, and engineers, but an
experience shared by the whole society. Christa made Challenger flight 51-L the most
publicized flight since the Apollo project over a decade earlier.
Other crew members included spacecraft commander Francis R. (Dick) Scobee,
pilot Michael J. Smith, mission specialists Judith A. Resnik, Ronald E. McNair, and
Ellison S. Onizuka, and payload specialist Gregory B. Jarvis. Scobee was a Challenger
veteran who flew its fifth orbital flight in 1984. Smith was selected as a NASA astronaut
in 1980 and was making his first space mission flight. Resnik, one of three mission
specialists on Challenger, became the second American woman to orbit during the flight of
Discovery STS-41-D. McNair was one of the first three Black Americans to enter the
astronaut cadre, and the second Black American in space in 1984 on the Challenger
STS-41-B. Onizuka, flying as a mission specialist on STS-51-C, was making his second
shuttle mission. Jarvis, like McAuliffe–not a federal government employee, was made
available for the Challenger flight by his company Hughes Aircraft, Space, and
Communications Group. His duties on the Challenger involved gathering new information
on the design of liquid-fueled rockets (The Crew?).
On top of McAuliffe?s ?dream come true? to accompany the Challenger mission,
the rest of the crew?s diversity led to even more public appeal: there were two
women–one an ordinary citizen, a Black American man McNair, a Hawaiian native born
to Japanese-American parents Onizuka, and two members of the crew who were not
federal employees (The Crew?). The coverage of this mission was special for the media
before it ever became tragic.
January 28th, 1986, was the coldest day that NASA had ever attempted to launch
a manned spacecraft. In fact, at 36 degrees Fahrenheit, it was 15 degrees colder than any
previous launch temperature (Mahal). Although lift-off time for the Challenger flight 51-L
had been delayed twice that morning, all operations and systems seemed to be under
control. An ?ice? team had been sent to the launch pad at 1:30 a.m. and again at 8:45 a.m.
and although there was some build-up, ice was cleared as a concern. Other weather
conditions were cleared by NASA staff over Cape Canaveral through the use of weather
balloons and also over the emergency landing site in Dakar, Senegal (Lewis 5).
The seven member crew arrived at the launch pad in the astronauts? van shortly
after 8 and were all strapped into their seats by 8:36 a.m. The large audience gathered at
the VIP observation site, excluding family and press, represented NASA?s pride of their
unique ?orbital classroom? mission. NASA officials invited hundreds of guests to see the
launch of 51-L, including McAuliffe?s third grade class from Kimball Elementary School
(McConnell 247). Educators, corporate sponsors of the Young Astronauts Council,
members of the Michigan Republican party organization, chairman, members of the
Teacher Astronaut Selection Panel, and a delegation from the People?s Republic of China
were also guests (Lewis 3). So, with all eyes watching, this is a first-hand experience from
the astronauts? families:
??Three, two, one?? [stated mission control]. ?Roger. Go with the throttle up,?
shuttle commander Dick Scobee radioed? His daughter Kathie, 25, huddled with
her mother, brother and infant son on a roof at Cape Canaveral, along with the
assembled families of the six other Challenger astronauts about to blast into space.
She felt the rumble of liftoff and hugged her baby closer in the cold. ?Wow, look
how pretty,? she said 74 seconds later. ?Is that normal?? someone else in the
crowd asked. ?They?re gone,? said Jane, wife of pilot Michael Smith. ?What do
you mean, Mom?? asked her son. ?They?re lost,? she replied. All over the country,
the millions watching that awful bloom spread across their television screens
realized that something had gone wrong before they heard the voice of mission
control: ?Obviously?a major malfunction.??
As schoolchildren everywhere gazed skyward, what Christa had promised would
be ?the ultimate field trip? (Downing) ended in disaster. The families were jostled off the
roof, down elevators, and into buses. Still dazed, Kathie clung to the baby Justin and eyed
the NASA staff. ?The looks on their faces told me that something was really, absolutely,
terribly wrong,? she recalls. The families waited for news in the crew?s quarters.
Christa?s husband Steve McAuliffe, with Scott, 9, and Caroline, 6, sat in Christa?s dorm
room. ?This is not how it?s supposed to be,? he whispered (Downing).
Rather than delivering the State of the Union address that evening as scheduled,
President Ronald Reagan made a brief speech. ?We?ll continue our quest in space,? he
promised traumatized Americans. ?There will be more shuttle flights and more shuttle
crews and, yes, more volunteers, more civilians, more teachers in space? (Downing).
There would be no shuttle flights for nearly three years. There would be no teacher in
space, and for those left on the ground, for the families of seven deceased astronauts,
there would be years of bitterness, grief and anger, and pain before their lives could finally
What went wrong? What actually happened to cause a veteran space shuttle such
as Challenger to dysfunction on its tenth run?
Challenger exploded 73 seconds after launch. At 0.68 seconds after ignition,
videotape showed black smoke coming from the bottom field joint of the right solid rocket
booster (SRB). The SRB comes in four segments that are assembled. The bottom field
joint is the lower joint on the SRB. The black smoke suggested that grease, joint
insulation, and rubber O-rings were being burned. The smoke continued to come from the
bottom field joint facing the exterior tank in cycles of three puffs of smoke per second.
The last puff of smoke was seen at 2.7 seconds. The black smoke was an indication that
the bottom field joint was not sealing correctly (Mahal).
At 58.8 seconds into flight, on enhanced film, a flame was seen coming from the
right SRB. The flame was coming from the underside of the bottom joint. It was burning
gas that was escaping from the SRB. A fraction of a second later, at 59.3 seconds, the
flame was well defined and could be seen without enhanced film. As the flame increased
in size, it had begun to push against the external tank due to the rushing air around the
The SRB is attached to the external tank by a series of struts that run alongside the
external tank. One of these struts is located at 310 degrees of the circumference of the
SRB. As the flame grew, it pushed against this strut with an intense heat of approximately
5,600 degrees Fahrenheit, making it hot and weak. The first sight that the flame was
hitting the external tank was at 64.7 seconds, when the color of the flame changed. Color
change indicated that the fire was being produced through mixing with another substance.
This other substance was liquid hydrogen, which is stored in the bottom external tank.
Pressure changes from the hydrogen tank confirmed that there was a leak (Mahal).
At 72 seconds there was a sudden chain of events that destroyed Challenger and
the seven crew members on board. By now, the lower strut connecting the right SRB to
the external tank was extremely hot and very weak. With the amount of force given by
the SRB, the lower strut broke away from both the right SRB and the external tank,
allowing the right SRB to rotate freely around the top struts. The bottom of the SRB
swung around hitting, denting, and burning Challenger’s wing. There was an extreme
force that shot the hydrogen tank forward into the oxygen tank causing them to burst. At
73.12 seconds into flight, a white vapor was seen from the bottom corner of the right
SRB. The white vapor was the mixture of hydrogen and oxygen. Only milliseconds after
the white vapor was seen, at 73.14 seconds, the glow turned into a fireball in a huge
explosion. The main explosion was the hydrogen and oxygen that came from the external
tank. Challenger was traveling at a speed of mach 1.92 at a height of 46,000 feet when it
blew up. The last recorded transmission from Challenger was at 73.62 seconds after
launch (Mahal). Michael Smith was recorded as saying, ?Uhh oh? (Lewis 16)!
Six days later, President Reagan, who was moved and troubled by the horrible
accident of mission 51-L, appointed an independent commission made up of persons not
connected with the mission to investigate it. The purpose of the commission was to: ?1)
Review the circumstances surrounding the accident to establish the probable cause or
causes of the accident; and 2) Develop recommendations for corrective or other action
based upon the commission?s findings and determinations? (Haggerty preface). The
commission was headed by Chairman, William P. Rogers, a former secretary of state
under President Nixon and former attorney general under president Eisenhower. Thus,
the investigative party became known as the ?Rogers? Commission. Other selected
persons included Vice-Chairman, Neil Armstrong, a previous NASA astronaut and federal
employee, as well as Sally Ride. The remainder of the commission was made up of David
Acheson, Eugene Covert, Richard Feyman, Robert Hotz, Donald Kutyna, Robert
Rummel, Joseph Sutter, Arthur Walker Jr., Albert Wheelon, Charles Yeager, and Alton
Keel Jr. (Haggerty commission).
Immediately after being appointed, the Rogers Commission moved forward in its
investigation with the full support of the White House. Although they held public hearings
dealing with the facts leading up to the accident, they felt the way to deal with a failure of
this magnitude was to disclose all the facts fully and openly. The commission took
immediate steps to correct mistakes that led to the failure and helped to renew confidence
and determination within NASA, in the eyes of the public as well as NASA itself. The
investigation?s main objective was not necessarily to point fingers, but to insure
confidence in NASA?s system for the public and men and women who fly the shuttles. It
focused its attention on the safety aspects of future flights based on lessons learned from
the assessment, with the aim being to return to safe space flight. (Haggerty preface).
At first, NASA seemed to be withholding information about the accident from the
public, press, and Rogers Commission. The press was declaring it a news ?blackout? by
NASA. A day later, in response to a question posed by Jay Barbree of NBC radio, Jesse
Moore, associate administrator of The Office of Space Flight, replied, ?I have not gotten a
briefing, Jay, on what the recovery team has found at this point in time. ?I have basically
looked at the NASA select photos and so forth, as you did, and all I can say is that it
appeared from those photos that there was an explosion. ?that?s about all I can say at
this point in time? (Lewis 27). Approximately two weeks following the tragedy, the
Rogers Commission was able to reassure the public that the full story was being told in an
orderly and thorough manner.
The consensus of the Rogers Commission and other participating investigative
agencies is that the loss of the space shuttle Challenger was caused by a failure in a joint
between the two lower segments of the right solid rocket booster (Haggerty 4). The solid
rocket booster’s segments are joined together by a tang and clevis joint. Each segment has
a tang on the bottom and a clevis on top. The clevis is the female connector, while the
tang is the male linking component. The bottom-mid segment connects to the bottom
segment with a nozzle. Where this occurs is called the bottom field joint. There are two
?washers? called O-rings that wrap around the clevis and seal the joint, as well as a zinc
chromate putty that is stuck in the joint. The bottom field joint is the joint that failed on
the right solid rocket booster (Mahal).
There were a few causes that could have lead to the joint seal failure: 1) Damage
or contamination could have occurred during the assembly. 2) The gap between the
joints had grown as a result of prior use of the solid rocket motors. 3) The temperature
on the day of the launch was 36 degrees; the temperature of the bottom right field joint
was 28 degrees at launch time. 4) The performance of the putty (zinc chromate) that was
applied to the joint (Mahal). 5) Overall construction of field joints made by Morton
Thiokol, the company that produces the SRBs for NASA. The results included a
combination of these possible causes.
Although a serious concern, damage and/or contamination of the field joints at the
time of assembly was ruled out as a contributing element of flight 51-L?s malfunction by
the Rogers Commission. Records showed that the segments were assembled using
approved procedures. Significant out-of-round conditions existed between the two
segments joined at the bottom right field joint. This caused a gap concern during
assembly, but test records show that the gap was in the acceptable range of error
Temperature was a key factor involved in failure of the field joint seal. On the
morning of the launch, the coldest joints were the bottom field joints of the right SRB.
Recall, that the temperature of that field joint was 28 degrees F. The temperature of the
opposite side was approximately 50 degrees F. When the O-rings are cold, they are very
stiff and do not move as quickly as they should. Out of twenty-one launches with
temperatures of 61 degrees F or greater, only four showed signs of O-ring thermal
distress. Each of the launches below 61 degrees resulted in one or more O-rings showing
signs of erosion of blow-by and soot (Haggerty 4). Tests were done to see how fast
O-rings seal at different temperatures. At 75 degrees F the O-rings seal within 530
milliseconds. On the opposite side of the scale an O-ring at 20 degrees F takes 1.9
seconds to seal (Mahal). It is this difference in time that most likely caused the explosion
of the Challenger.
The performance of the putty is another probable cause of the joint seal failure.
The zinc chromate putty is placed on the inside of the joints and also forced between the
gap of the tang and clevis during assembly. It is there to stop combustion of hot gas from
reaching the O-rings. The hot gases can make holes in the putty, thus letting gas go
through to the O-rings which could cause damage (Mahal). Prior to the tenth launch of
the Challenger, the company that had been producing the putty for the SRB joints went
out of business. Putty had to be obtained from a new source and post-testing showed that
it was more susceptible to environmental effects; moisture made it tackier (Lewis 83).
Due to the launch temperature being very significant, the Rogers Commission took this
finding into account as a contributing factor.
The Rogers Commission found that the failure was due to a faulty design
unacceptably sensitive to a number of factors (reusability, putty and O-ring performance in
adverse temperatures). The investigative party concluded that the company producing the
O-rings, Morton Thiokol, and NASA were guilty of allowing an avoidable accident to
occur (Downing). This accident was deemed avoidable through research done on both
companies? engineers, prior memorandums sent between the companies and department
heads, and events that took place on the eve of flight 51-L.
On July 31st, 1985, Roger Boisjoly, Staff Engineer in applied mechanics at Morton
Thiokol, sent a memo to Robert Lund, Thiokol?s Vice President of Engineering, urging
that Thiokol?s unofficial task force originally ?said? to be assigned to the field joint
problem officially be pulled from their regular duties and actually assigned to the problem.
The memo concluded, ?It is my [Roger Boisjoly] honest and real fear that if we do not
take immediate action to dedicate a team to solve the problem with the field joint having
the number one priority, then we stand in jeopardy of losing a flight along with all the
launch pad facilities? (Vaughan 448).
Prior to this task force request?eight years prior, NASA and Morton Thiokol
both new that the solid rocket boosters were poorly designed. In that period of time
nearly every launch had been recorded as having some type of erosion with the infamous
O-rings. When Roger Boisjoly voiced his concern, nearly a year and a half before the
launch of the Challenger, the department heads nonchalantly assured him that it was being
worked on. A message sent in August of 1985 from the project engineer recognized the
problem, stated that long term solutions looked good, and simple short term measures
should be taken to ?reduce flight risks? (Vaughan 449). The long term solutions were
projected to require several years. Shuttles had already been at risk, and for the time
being would remain at risk.
The night before the fatal launch, a number of engineers voiced their concerns.
Roger Boisjoly and others advised that a launch temperature of 53 degrees Fahrenheit was
crucial for proper functioning of the field joints? O-rings (Vaughan 338). Chief executives
and heads argued with sarcasm asking the engineers why they thought 53 was the magic
number? The Rogers Commission later found that head executives of Morton Thiokol
were in agreement with the lower level research engineers until they found out that NASA
was considering other companies to build the rocket boosters. Not wanting to lose their
biggest client, Thiokol heads changed theirs minds a few days before the 28th to act in the
?best interests? of the firm–to go a head with the launch (Vaughan 337). This provided
an even tougher challenge for Boisjoly and company to change anyone?s mind on the
launch eve. He later states, ?This was a meeting where the determination was to launch,
and it was up to us to prove beyond a shadow of a doubt that it was not safe to do so.
This is in total reverse to what the position usually is in a preflight conversation or a flight
readiness review? (Vaughan 338).
The engineers were ignored. No one went to the press or a member of Congress.
No one tried to reach the astronauts and inform them of the risks they were taking if they
launched the following morning. High-level engineers told NASA what it wanted to hear,
and low-level engineers held their breath and went back to work. These were the reasons
the Rogers Commission found NASA and Thiokol guilty of an ?avoidable? accident.
NASA?s rush to launch despite engineering objections is typical of American
corporate behavior. Although NASA is a government agency, not a business, by trying to
make the shuttle commercially practical, NASA subjected its operations to business
considerations almost from the beginning. Furthermore, the agency is essentially a
coordinator of the work of a large number of private corporations, where most of the
engineers and technicians that were at question were employed.
The shuttle explosion is just ?another example of the acceleration degradation of
the status of the engineer in the American corporation,? says Ralph Nadar, a chemical
engineer at Union Carbide (Lindorff 880). The profit motive for the companies seemed to
be overriding engineering concerns at exactly the time when the engineer?s views were
crucially important. What happened at NASA and Morton Thiokol is a useful lesson for
corporations: not only were the engineers overruled by the management, they were so
afraid of retaliation that they didn?t go outside the chain of command. Other than honest
ethical practices, they had a reason to be. Thiokol?s first reaction to the disaster was to
punish Roger Boisjoly and Allan McDonald, Director of Solid Rocket Motors. These two
were the main culprits of presenting the contradicting launch evidence on the night before
the launch and also the engineers who testified exclusively before the Presidential
Commission. For this, Thiokol decided to punish them by reassigning them and reducing
their responsibilities (Lindorff 880).
Intimidation plays a huge role in corporate America. When a ?whistleblower,? a
lone guy making noise (Lindorff 881), raises a complaint, the most simple alternative for
the company is dismissal. The lack of individual protection, especially for engineers, is
causing a decaying hole in the code of ethics. Boisjoly and McDonald knew exactly why
they felt the launch of the Challenger should have been delayed again, but after being shot
down and shut out by upper level management that night, they turned away with their
fingers crossed and accepted their attempt as good enough, fearful of who else to turn to.
By noon the next day, the engineers had second thoughts on letting consequences guide
their ethical decisions.
A quote by Seymour Melman, an industrial engineer at Columbia University, from
Lindorff?s article depicts just how terrible unacted upon ethical decisions can be in
??In the Soviet Union it?s called democratic centralism?you argue and debate
until the leadership reaches a decision, and then you shut up and go along. Here
in the United States it?s just called putting on your management cap. In the end,
they?re the same thing. The only difference is that here [in America], after a
disaster, you learn about it because we have a tradition of independent
institutions, like The New York Times or National Public Radio.?
On January 28th, 1986, the independent institutions certainly did not fail the
nation. Live national press coverage let even the most rural communities join in and feel
like part of the event. Somehow NASA and Christa McAuliffe had created something so
wonderful that it joined the American people as if there was an invisible flow of holding
hands nationwide. NASA was an impenetrable superpower and it made the people feel
If you asked me personally where I was in the late morning on that day of January,
I could tell you very explicitly. My entire third grade class at Sandoz Elementary School
had been given the privilege to watch the launch with other classes in the library. We had
been covering the Challenger mission for weeks in class, preparing for the date with
anticipation. Just prior to our lunch and recess period we all sat Indian-style on the floor
waiting for the moment quietly. As I watched the shuttle ascend and disappear, exploding
in the smoke, denial set in. I thought I had missed something, or the station was showing
footage of a previous disaster. Realization of the truth didn?t set in until later when our
teacher had the unsettling task of explaining to the class what actually did happened.
A study conducted in 1993 published in Change magazine by Arthur Levine,
revealed some interesting views of college students of that generation. Twenty-eight
collegiate institutions were visited by Levine and other colleagues, where they met with
eight to ten students per institution. The question posed was, what social and political
events had most influenced their generation? Five common answers were given. The
most frequent answer was the Challenger explosion. It seemed that once one student
mentioned it, other members of the group would begin by shaking their heads in
agreement and then continue conversing about it in an open discussion. Levine states, ?It
was the equivalent of the Kennedy assassination for this generation.? All the students
knew where they had been when they heard the news; most had watched it on television in
school. Some had been scheduled to have the teacher-astronaut Christa McAuliffe teach
them from space. As students talked about their first shared generational tragedy in the
sense that it shattered both their idealism and their feeling of security, Levine remembers
some of their quotes: ?I always thought NASA was perfect.? ?There were smashed
dreams because of it.? ?My hopes were in it. There was an Asian, a Black, and two
women.? Levine concludes by realizing that the relationship between Christa McAuliffe
and this generation felt so personal to them, that for many it was their first brush with
As NASA looks to the future, finding ways to go higher, faster, and farther, the
tragedy of mission 51-L will never be forgotten. Few of the administration from 1986 still
work for NASA, but despite this, the program as a whole is continually searching to
upgrade safety procedures and equipment. The crew of the ill-fated Challenger have
staked their claim in the history books and due to the extensive media coverage, frozen
images in peoples? minds that might last forever. Whenever dealing with risky technology,
accidents are bound to happen. It?s truly too bad that such a collaborating, heart-felt
event had a tragic end that crushed America?s social invincibility. The past has a quality of
repeating itself, and when NASA?s unlucky day comes up again, it will most likely set the
scale for the most covered space mission in history, again.
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Levine, Arthur. ?The Making of a Generation.? Change Sept.-Oct. 1993: 10-11.
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